use strict;

sub processURL {
    my $manifest = shift;
    my $url = shift;
    my $storepaths2urls = shift;
    my $urls2hashes = shift;
    my $successors = shift;

    $url =~ s/\/$//;
    print "obtaining list of Nix archives at $url...\n";

    system "wget --cache=off '$url'/MANIFEST -O '$manifest' 2> /dev/null"; # !!! escape
    if ($?) { die "`wget' failed"; }
        
    open MANIFEST, "<$manifest";

    my $inside = 0;

    my $storepath;
    my $narname;
    my $hash;
    my @preds;

    while (<MANIFEST>) {
        chomp;
        s/\#.*$//g;
        next if (/^$/);

        if (!$inside) {
            if (/^\{$/) { 
                $inside = 1;
                undef $storepath;
                undef $narname;
                undef $hash;
                @preds = ();
	    }
            else { die "bad line: $_"; }
        } else {
            if (/^\}$/) {
                $inside = 0;
                my $fullurl = "$url/$narname";

		$$storepaths2urls{$storepath} = $fullurl;
		$$urls2hashes{$fullurl} = $hash;

                foreach my $p (@preds) {
		    $$successors{$p} = $storepath;
                }

            }
            elsif (/^\s*StorePath:\s*(\/\S+)\s*$/) {
                $storepath = $1;
            }
            elsif (/^\s*NarName:\s*(\S+)\s*$/) {
                $narname = $1;
	    }
            elsif (/^\s*MD5:\s*(\S+)\s*$/) {
                $hash = $1;
            }
            elsif (/^\s*SuccOf:\s*(\/\S+)\s*$/) {
                push @preds, $1;
            }
            else { die "bad line: $_"; }
        }
    }

    close MANIFEST;
}


return 1;